SUCCESSIVE DEVELOPMENT OF THE SPORES.
When the spore is to cease to be a spore, and to become a mushroom, the first thing it does is to send forth certain cotton-like filaments, whose interfacings entangle it completely while they also serve to attach it to the place of its birth; these threads (like the spongioles attached to the roots of phænogamous plants, whose name sufficiently explains their office) absorb and bring nourishment to the quickened spore, which then maintains itself entirely by intus-susception. All this takes place before the germ has burst, or the embryo fungus begun to develope its organs. In some instances, these elementary threads are, like the ordinary roots of plants, spread out to a considerable distance underground, forming here and there in their course small bulbs or tubercles, each of which, in turn, becomes a new individual; in others, and more commonly, these spores are sprinkled about unconnectedly, as in the Pietra funghaia, affecting certain spots only, which become so many small matrices whereof each furnishes a crop. The union of many germinating granules together with their connecting threads, constitutes mushroom spawn, or, as it is technically called, carcytes.[110] Examined a short time after quickening, the spore is found to have swelled out into a fleshy kernel; which in puff-balls, truffles, and the uterine subterranean families generally, constitutes of itself the whole fungus; this only grows in size afterwards, the substance and original form remaining the same through the entire period of development. In those destined to live under the influence of air and light, this same rudimental nucleus gradually evolves new parts, and assumes, as we have seen, a vast variety of forms, (whereof each particular one is predetermined by the original bias imprinted upon every spore at its creation,) and here there is a manifest analogy with the progressive development of new parts in the higher plants. In such funguses as are wrapped up in a volva or bag, during the earliest period of growth, this furnishes them not only with the means of protection, but of nourishment also. This volva, which is formed by the mere swelling out of the original fleshy bulb, when it has grown to a certain size, exhibits towards its centre the rudiments of the young fungus; of which the receptacle appears first, and all the other parts in succession. The embryo, next taking to grow, in its turn approaches the circumference of the volva, which, having by this time ceased to expand, is burst open, and sometimes with much violence, by the emerging Amanite. As soon as the hymenium has parted with its seed, which falls from it in the form of fine dust, the fungus, collapsing, either withers on its stem, or else dissolves into a black liquid and so escapes to the earth. In such funguses as have not a volva, the basilar or primary nucleus shoots up at once in the form of a cone, and a little later presents at its apex the rudiments of a receptacle or head; by degrees, and frequently by slow degrees,[111] the perfected structures of the plant are elaborated and spread themselves out into some of the forms mentioned above, of which the clavate is the most simple, and that with gills the most complex. The primary nucleus is formed out of simple cellular membrane, the cells of which, at first elongating, and at length uniting into little bundles, assume a fibrous appearance; sometimes these fascicular bodies effuse themselves unchanged into the substance of the receptacle, in which they spread out and are lost; at others, a transverse line makes the demarcation between the pileus and stem.[112] The last part formed in a fungus, generally, is that which bears the seed; and whenever an exception to this occurs, and the seed is formed at an earlier period than usual, nature has in this case provided three membranes, to cover and protect these delicate organs till the plant shall have attained maturity: these are the ring (annulus), the veil (velum), and the wrapper (volva).